1. Field of Invention
The invention relates to a waterproof shoe structure, which comprises at least part of a shoe and includes an outer layer, a lining with a waterproof but water-vapor permeable functional layer, a lining sole, an insole and an outsole.
2. Description of Related Art
Shoes with a shoe structure which includes a lining fitted with a waterproof and water-vapor permeable functional layer are widely known, as is their high degree of wearing comfort. Constructing shoes of this kind in a watertight manner is always problematic when the shoe includes seams, e.g. those used to attach the lining. Water can be drawn in through seam lines of this kind by capillary action and is able to penetrate to the inner area of the shoe. In the most simple embodiment, the functional layer is inserted in the form of a sock (which has become well known as a `booty`, see EP-0 080 710 A2), which is only connected to the outer layer at the top opening of the shoe. In this embodiment, the lining which contains a functional layer is also present in the sole area of the shoe, which is often unnecessary, since the outsole itself is usually not water-vapor permeable. Moreover, the time and expense involved in constructing the lining in the form of a sock is often too high for many applications.
Consequently, the shoe structure described in WO 96/41549, which is not constructed as an embodiment with a sock, is an improvement. In that case, an insole is used in addition to the lining which contains a functional layer. The lower end area of the lining is turned back to the inside in the sole area and positioned approximately parallel to the outsole. In this end area and at the extreme edge of the lining, the functional layer is bonded to the synthetic material of the sole in a waterproof manner, which guarantees that the shoe is watertight.
WO 97/24940 describes a waterproof shoe structure with an insole and a bonded outsole. In this shoe structure too, the lower end area of the lining is turned back to the inside in the sole area and positioned approximately parallel to the sole. The end area which is turned back and the insole lie at the same level and are connected to each other. The watertightness of the shoe is achieved by bonding the surface of the outsole at least to the end area of the functional layer of the lining which is turned back.
In order to guarantee on production that the shape of the shoe structure is maintained, pieces of netting produced from monofilaments are used in both the cases mentioned; these pieces of netting are positioned parallel to the insole and are connected to the lower ends of the outer layer, either at least in the ankle area or across the entire extent of the foot area. Sewing these retainers to the outer layer involves considerable time and expense in the manufacturing process.